drivers/of: Constify device_node->name and ->path_component_name

Neither of these should ever be changed once set. Make them const and
fix up the users that try to modify it in-place. In one case
kmalloc+memcpy is replaced with kstrdup() to avoid modifying the string.

Build tested with defconfigs on ARM, PowerPC, Sparc, MIPS, x86 among
others.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Julian Calaby <julian.calaby@gmail.com>
diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
index ffb93ae..01b62a6 100644
--- a/arch/powerpc/sysdev/fsl_pci.c
+++ b/arch/powerpc/sysdev/fsl_pci.c
@@ -136,7 +136,7 @@
 	u32 pcicsrbar = 0, pcicsrbar_sz;
 	u32 piwar = PIWAR_EN | PIWAR_PF | PIWAR_TGI_LOCAL |
 			PIWAR_READ_SNOOP | PIWAR_WRITE_SNOOP;
-	char *name = hose->dn->full_name;
+	const char *name = hose->dn->full_name;
 	const u64 *reg;
 	int len;